Part 1: He Mode Interference Removal for Spectral Clarity and Multi-Isotope Confirmation
The contribution that collision/reaction cells (CRC) can make to improving ICP-MS data quality by removing spectral interferences has been well documented. Similarly the potential for data quality to be degraded by the creation of new interferences or the loss of analyte sensitivity by reaction has also been widely discussed. However, the use of an inert cell gas (helium mode) and interference removal using kinetic energy discrimination (KED) not only avoids these problems, but also has the added benefit that it can effectively remove any polyatomic interference, rather than being suitable only for interferences which react with the chosen cell gas. This avoids the issue of incomplete removal of unreactive interferences, and allows helium (He) mode to be considered as a "universal" cell mode, being applied to almost all analytes in virtually any sample type.
Although not as widely recognized, a further benefit of He mode is that it can remove the polyatomic interferences from all isotopes of the target elements, so allowing the user to measure additional isotopes for many analytes. This approach is widely used in organic mass spectrometry, where these secondary ions are referred to as "qualifier" ions. In the first webinar of this series, we will assess the fundamental performance of He mode in removing spectral interferences in ICP-MS, thereby making such qualifier ions available for evaluation of data quality. In the second webinar of the series (scheduled for 10 February 2010) we will present data demonstrating the use of qualifier ions to improve ICP-MS data quality in complex sample matrices, by confirming the measured result from the primary isotopes.
Part 2: Using Qualifier Isotopes to Validate Multi-Element ICP-MS Data in Complex Sample Matrices
In Part 1 of this ICP-MS seminar series, we showed how a Collision Reaction Cell operating with an inert cell gas, helium (He), can improve ICP-MS data quality by removing the matrix-based polyatomic interferences that affect many analytes in complex sample types. The fact that He mode is universal (in that it is effective for all polyatomic ions, not just reactive ones) enables more information to be extracted from the ICP-MS spectrum, because removing the polyatomic interferences from all isotopes of each analyte allows the analyst to use a second isotope as a qualifier ion to confirm the results measured at the primary (or preferred) isotope.
In the second seminar of the series, we will show how this qualifier ion capability is addressed in current and upcoming regulations and methods for ICP-MS sample analysis, and how such qualifier ions can be applied to the measurement of routine samples in the real laboratory situation. We will show data demonstrating the use of qualifier isotopes to assess data quality for many potentially interfered analytes (including most of the first row transition elements) across a wide range of complex sample types, including commonly-used interference check solutions and representative high matrix samples from a typical environmental laboratory. In addition to illustrations focusing on the data obtained using He mode, we will also evaluate the potential improvement in data quality that He mode provides, by comparing the results obtained for multiple isotopes in a variety of measurement modes: He mode, reaction mode and no gas mode (equivalent to conventional non-cell ICP-MS).
Your Speakers:
Ed McCurdy
ICP-MS Product Manager
Life Sciences and Chemical Analysis Group
Agilent Technologies
Steve Wilbur
ICP-MS Environmental Marketing
Chemical Analysis Solutions Group
Agilent Technologies
